Lock and alarm

ABSTRACT

A lock and alarm including a bolt and a compression spring located in a bolt casing. A latch is attached to the bolt and moves in a slot to a holding position to retract and hold the bolt. The latch is released to move the bolt to a position where it engages a portion of the receiver. When the bolt is moved off the engaging portion the spring moves it into the receiver and at the same time the latch controls a switch to actuate an alarm.

ite States Patent Maged 1 1 Nov. 26, 1974 1 1 LOCK AND ALARM [76]Inventor: Mitchell Maged, 123 Berkshire Rd.,

Rockville Centre, NY. 11570 22 Filed: Mar.21, 1973 21 Appl. No.: 343,357

[52] U.S. Cl 340/274, 340/276, 292/340, 292/175, 200/6168 [51] Int. Cl.G08b 13/08 [58] Field of Search 340/274, 276, 275; 70/432, 70/434, D16.49, 279; 292/33, 121, 122,

163, 164, 169.12, 340, 175; ZOO/61.64,

[56] References Cited UNITED STATES PATENTS 1,604,540 10/1926 Ta ggart,.lr 292/341.l3 X 2,756,300 7/1956 Thiberville 340/274 UX 2,842,6317/1958 Martens ZOO/61.67

3,196,293 7/1965 Howard .1 340/274 X 3,402,405 9/1968 Contreras 340/2743,587,080 6/1971 Hawkins 340/274 3,751,088 8/1973 Schlage 70/279 X3,768,087 10/1973 Kaye 340 274 Primary Examiner-John W. CaldwellAssistant Examiner-Wi11iam M. Wannisky Attorney, Agent, or Firm-Darby &Darby [57] ABSTRACT A lock and alarm including a bolt and a compressionspring located in a bolt casing. A latch is attached to the bolt andmoves in a slot to a holding position to retract and hold the bolt. Thelatch is released to move the bolt to a position where it engages aportion of the receiver. When the bolt is moved off the engaging portionthe spring moves it into the receiver and at the same time the latchcontrols a switch to actuate an alarm.

6 Claims, 3 Drawing Figures PATENTE; waves 1914 3,851.32 5

This invention relates to a locking and alarm system and moreparticularly to a device which is automatically operated to provide alock and to trigger an alarm when a normally closed opening, such as adoor, is partly opened.

Security devices are often used in addition to conventional locks toprotect stores, homes, apartments, and other places against entry by anunauthorized intruder. In the case of a door, conventional door locksusually can be easily forced by an intruder. For example, a simplepassage lock, which is part of the door knob, sometimes can be forcedmerely by inserting a piece of stiff material between the door and thejamb to move back the bolt. Other locks, having keyholes on the outsideof the door, can be picked or opened with master keys. In addition noneof the foregoing types of locks can provide an alarm when unauthorizedentry is attempted.

In the Contreras U.S. Pat. No. 3,402,405, a selflocking burglar alarmsystem is provided which uses a spring biased bolt arm which extendsacross and through opposite walls of a housing. An audible alarm andswitching means are also located in the housing.

One end of the bolt arm engages a latch plate near an opening while theother end is used tomove the arm back to extend the spring to cock it.When the window or door on which the alarm is mounted is moved, the endof the arm moves off the latch plate into the opening to provide a lock.At the same time the arm actuates the switching means to trigger thealarm.

While the device of the Contreras patent is operative, it has severaldisadvantages. First of all, the structure does not lend itself tomanufacture to produce a heavy duty lock. In addition, since the end ofthe arm opposite the one engaging the latch plate extends out of thehousing, it can be reached through a window opening,

if available, to disable the alarm. Further, the coopera- I tiverelationship of the operative end of the bolt arm and the latch plateare such that it is possible for an intruder to move the bolt arm to aninoperative position from outside the area being protected.

It is therefore an object of the present invention to provide a novel,self-locking alarm device of strong and secure construction. Inaccordance with the invention, the device includes an alarm housinghaving a bolt casing in its interrior holding a solid and sturdy bolt.An audible alarm and a switching device is also located in the housing.The bolt has a slot along a portion of its length which terminates in anend providing a latching, or rest, position for a latch attached to thebolt. The latch is operated to move the bolt against the force of thespring to place it in its latched position or to place the lock andalarm in the ready position.

The alarm device cooperates with a receiver, also of sturdyconstruction, which includes an internal shoulder on which the operativeend of the bolt rests when the alarm is in the ready" position. Thismakes the bolt less accessible to movement by the intruder. When thedoor or window is moved, the bolt moves off the shoulder to make thelock and also carries the latch pin to actuate the alarm.

The latch pin is generally transverse to the bolt and extends through aplate covering the housing plate through which the latch pin extends.This makes latch pin somewhat more inaccessible to operation by anintruder who could place his hand through a window. In

addition, in a preferred embodiment the latch pin is made of two piececonstruction so that one piece can be removed making it relativelyimpossible for an intruder to deactivate the alarm.

It is therefore an object of the present invention to provide aself-locking alarm of sturdy construction.

It is a further object to provide a lock and alarm utilizing a boltwhich is biased by a compression spring, both the bolt and thecompression spring being located in a bolt casing.

A further object is to provide a self-locking alarm device having amovable bolt which engages a recessed lip portion of a receiver.

Other objects and advantages of the invention will become more apparentupon reference to the following specification and annexed drawings, inwhich:

FIG. 1 is a plan view, shown with the cover and bolt receiver partlybroken away;

FIG. 2 is a top view taken in cross-section along lines 2-2 of FIG. 1showing the device in the ready" position; and

FIG. 3 is a view similar to FIG. 2 showing the bolt in the actuatedposition.

The lock and alarm unit includes a lock 10 and a receiver 12. Lock 10includes a housing 13 of generally rectangular shape preferably formed,such as by casting, from one piece construction from a suitable sturdymetal material. Housing 13 includes upstanding walls 14a, 14b, 14c and14d each having an internal recessed lip 15 on its upper edge. A numberof holes 18 are formed in the housing bottom wall, or through anupstanding post 19 (FIG. 2) to accommodate screws 20 which fastenhousing 13 to an operating member such as a door D. The door is ofconventional construction and can be of wood, metal or other suitablematerial.

A tapped hole 22 is formed in an upstanding post 23 formed on top of abolt receiver casing 25. A screw 26 fastens a cover plate 27 to thehousing. Cover plate 27 rests in the lip 15 on walls 14. With the coverplate 27 on, the screws holding housing 13 to the door are unaccessible.

Where housing 13 is of cast construction, a generally rectangular guidebolt casing 25 is also cast with a generally cylindrical interior bore28 terminating at one end in back wall 29. 'A guide slot 31 is formedthrough a portion of the length of casing 25 parallel to the axis ofbore 28. A latching slot 33 is also formed in a portion I of thecircumference of the casing generally transverse to guide slot'31. Alatching lip 34 is formed on a portion of one wall of slot 33 to form anotched area, including a wall 35 at the end of guide slot 31, in whicha latch pin can latch.

A locking bolt 37 of generally cylindrical shape is slidably carried inthe bore 28. Locking bolt 37 is preferably solid, and of rigid metalconstruction. Bolt 37 has a hole 39 for holding one part, pin 41, of theoperating latch 42. The operating latch also includes an extension 43terminating in a knob 44. Extension 43 is telescoped and force fit overpin 41. Pin 41 can be a roll pin so that it can be held in hole 39without requiring threading or machining. A coil spring 45 is heldbetween the back wall 29 of casing 25 and a recess 46 in the rear end ofbolt 37. Latch member 42 limits the travel of bolt 37 to the length ofslot 31.

As seen in FIG. 1, cover plate 27 has a slot which includes a straightportion 48 and a curved or arcuate cover slot portions 48, 49 overlieand are spaced from slots 31, 33 in the bolt casing 25. As seen in FIGS.2-3, the latching member 42 extends through the slot 48, 49 and ismovable therealong.

An upstanding support block 55 is formed on the interior of housing 13and has a recessed portion between two upstanding walls 56. A switch 58is mounted between and held in place by a suitable adhesive, such as anepoxy cement. Switch 58 includes leaf-spring members 59a and 59b havingrespective contact points at one end. Member 59a has an extension lyingin the path of travel of latch pin 42. The back end of each member 59 issandwiched between insulating members 60 mounted on support post 55. Therear end of member 59a is electrically connected to block 55 to place itat the common potential point of an electrical circuit. The circuitincludes one or more batteries B held in a conventional battery case 62suitably fastened to the bottom wall of housing 13. Two batteries B areshown arranged in series circuit with one terminal of case 62electrically connected by a wire 63 to the rear of switch member 59b andthe other terminal connected by a wire 64 to an. audible alarm 66.Openings 67 are formed in the cover plate opposite alarm 66 for thealarm sound to pass through. Alarm 66 preferably has a metallic casewhich is connected tohousing 13 and the common potential point. When thecontacts of the two switch members 59a and 5% are closed, the electricalcircuit is completed and the alarm operates.

The bolt receiver 12 is a case of generally rectangular shape alsopreferably cast from sturdy metal. A pair of ears extend outwardly andeach has a hole 70 therein through which a screw 72 passes to fastenreceiver 12 to a fixed point, for example, a door jamb J. A strikerplate (not shown) can be part of the receiver 12 to extend transverse tocars 70 into the space between the door and jamb to provide additionalstructural strength in fastening the receiver to the jamb. Where astriker plate is used the jamb would be recessed to make the plateflush.

The interior of receiver 12 is a hollow cavity 76. A step or ledge 77 isformed across the length of the receiver to provide a lip, or shoulder,78 against which the operative end of bolt 37 rests when the device isin the ready position, as explained below. Receiver 12 is preferablymounted so that shoulder 78 lies inwardly of the edge of jamb.

Both the lock and receiver 12 are mounted on the inside of the areas tobe protected. Therefore, they are not visible to an intruder. Ingeneral, there will be another lock (not shown) on the door.

To operate the device, the alarm can be placed in an inoperativecondition by moving the latch 42 in the cover plate slot 48 against theforce of spring 45 to the right, as shown in the figures. It is thenmoved down and around projection 50. The latch 42 is released and thepin 41 comes to rest in the notched area at the end of guide slot 31 andlatches against the wall 35. Locking bolt 37 will clear the receiver sothat the door can be opened and closed in the normal manner.

To place the alarm lock in the ready" position, the door is closed andthe latch 42 is moved upwardly back around the projection 50. This movespin 41 away from shoulder 35 and bolt 37 is moved to the left by spring45. As seen in FIG. 2 the front end of bolt 37 extends partly beyondhousing wall 14b and comes to rest against receiver shoulder 78. Switchcontacts 59a and 59b are still open since the latch 42 is spaced awayfrom the extension of 59a. Thus, the alarm will not be actuated. Spring45 is still partly compressed and has stored energy.

' When the door is moved a small amount, as shown in FIG. 3, the end ofbolt 37 rides off shoulder 78. The spring 45 isnow free to extend andquickly moves the bolt into the receiver locking cavity 76 to form alock against any further door movement. A large portion of the length ofbolt 37 remains in casing 25 to provide a rigid and secure lock. As thebolt moves, latch 42 engages and carries switch member 59a toward member59b to close the electrical circuit. The alarm sounds, indicating thatan attempt has been made to open the door. Thus, the door is locked andan alarm is sounded in the same action.

To stop the alarm, the door is closed and the latch is moved to move thebolt to the inoperative position.

The lock alarm has several advantages. The components such as thehousing 10, receiver 12 and bolt 37 are of sturdy construction. Inaddition bolt 37 which is guided in a strong casing. This reduces thelikelihood that the alarm can be disabled by breaking the bolt.

In addition, once the alarm has been set (FIG. 2), the

latch extension 43 can be removed. Pin 41 is made of sufficient heightto engage switch member 59a even if extension 43 is removed. This is anadvantage'since, for example, in the case where the lock alarm is usednear a window, an intruder cannot disable the alarm by cutting thewindow, putting his hand through, and moving the bolt back to theinoperative position.

The engagement of the switchcontacts by the pin 41, or extension 43provides positive actuation of the electrical circuit.

The use of the coil spring 43 in casing 25 also provides a positiveacting arrangement. The spring is fully concealed and guided in casing25. It can exert a substantial force to rapidly move the locking boltinto locking position (FIG. 3) and hold it there. Some prior art lockingdevices, for example, the Contreras patent require that the spring beextended when in the ready position (FIG. 2'). This makes the springmore susceptible to breaking.

The fact that the shoulder 78, which engages the end of the bolt in theready position, extends partly in from the edge of the door jamb edge isalso advantageous. This arrangement makes it more difficult for anintruder to insert a device in between the door and the jamb to attemptto move the bolt backward.

What is claimed is:

1. A lock and alarm device comprising in combination a receiver meansincluding an opening; a housing including a first upstanding walldefining an opening, an elongated guide bolt casing formed on theinterior of the housing and having a central bore which terminates atone end in an opening at said first housing wall and at the other end ata wall of said casing, said casing also formed with an elongated throughslot into said bore having a first portion generally parallel to thelongitudinal axis of the bore along at least a part of the lengththereof and a second portion which is at an angle to said first portion,an elongated bolt in said casing bore and a spring between one end ofsaid bolt and said casing wall at said other end of said bore, a coverplate attached to said housing and having a slot formed therein with anelongated generally straight first portion corresponding to said firstportion of the casing slot, and a curved second portion including atleast a part corresponding to said second portion of said casing slotand defining a projection on the plate, a latch pin attached to andgenerally transverse of said bolt and movable in said casing slot andhaving a portion extending through said cover plate slot and movabletherein;.audible alarm means located in said housing, switch means insaid housing connected in electrical circuit with said alarm means andhaving an actuating means in the path of travel of said latch pin, saidpin when moved around said projection in said cover plate and resting ina first position against the wall forming said second portion of saidslot to hold said bolt in a retracted position with said springcompressed in said bore, said pin being movable in said first portion ofsaid cover slot from said first position around said projection of saidcover plate into an intermediate position when one end of said boltremote from the end engaged by the spring engages a fixed part adjacentsaid opening of said receiver means, said one end of said bolt beingcarried into said receiver opening to a second position by saidcompressed spring being released as said one end is moved off said fixedpart, said pin carried by said bolt as it is moved to said secondposition engaging the switch actuating means to complete the electriccircuit with the alarm means. I

2. A device as in claim 1 wherein said latch pin is formed of twopieces, one of which is inserted through the slot on the plate toconnect with the other piece attached to the bolt.

3. A device as in claim 1 wherein said switching means includes at leastone switch contact mounted on a leaf spring, said leaf spring comprisingsaid switch actuator means which is engaged by said latch pin.

4. Apparatus as in claim 1 wherein said fixed part adjacent saidreceiver means engaged by said one end of said bolt comprises a step onsaid receiver means recessed from the exterior of said receiver means.

5. A look and alarm device comprising a housing including an upstandingwall defining an opening, a guide bolt casing formed on the interior ofthe housing and having a central bore which terminates at one end in anopening at said housing wall and at the other end at a wall of saidcasing, said casing also formed with a through slot into said borehaving a first portion generally parallel to the longitudinal axis ofthe bore along part of the length thereof and a second portion which isat an angle to said first portion, a bolt in said casing bore and aspring between one end of said bolt and said casing wall at said otherend of said bore, a latch pin attached to said bolt and movable in saidslot, audible alarm means located in said housing, switch means in saidhousing connected in electrical circuit with said alarm means and havingan actuating means in the path of travel of said latch pin, said pinwhen resting in a first position on the wall of said second portion ofsaid slot holding said bolt in its retracted position and said spring ina compressed condition in said bore, said pin when fully released fromsaid first position carried by said bolt as it is moved by thereleasedspring to a second position engaging the switch actuating means tocomplete the electric circuit with the alarm means, a cover plate forsaid housing, said cover plate having a slot therein which generallycorresponds to the shape of the slot in the bolt casing and is adjacentthereto, said latch pin formed of two pieces, one of which is attachedto said bolt and the other of which is inserted through said slot of theplate to connect with said one piece.

6. A device as in claim 5 wherein said slot in said plate has anelongated generally straight first portion corresponding to said firstportion of the casing slot, and a curved second portion defining aprojection in the plate, said pin being movable in said curved secondportion around the plate projection to place said latch pin in saidfirst position.

1. A lock and alarm device comprising in combination a receiver meansincluding an opening; a housing including a first upstanding walldefining an opening, an elongated guide bolt casing formed on theinterior of the housing and having a central bore which terminates atone end in an opening at said first housing wall and at the other end ata wall of said casing, said casing also formed with an elongated throughslot into said bore having a first portion generally parallel to thelongitudinal axis of the bore along at least a part of the lengththereof and a second portion which is at an angle to said first portion,an elongated bolt in said casing bore and a spring between one end ofsaid bolt and said casing wall at said other end of said bore, a coverplate attached to said housing and having a slot formed therein with anelongated generally straight first portion corresponding to said firstportion of the casing slot, and a curved second portion including atleast a part corresponding to said second portion of said casing slotand defining a projection on the plate, a latch pin attached to andgenerally transverse of said bolt and movable in said casing slot andhaving a portion extending through said cover plate slot and movabletherein; audible alarm means located in said housing, switch means insaid housing connected in electrical circuit with said alarm means andhaving an actuating means in the path of travel of said latch pin, saidpin when moved around said projection in said cover plate and resting ina first position against the wall forming said second portion of saidslot to hold said bolt in a retracted position with said springcompressed in said bore, said pin being movable in said first portion ofsaid coVer slot from said first position around said projection of saidcover plate into an intermediate position when one end of said boltremote from the end engaged by the spring engages a fixed part adjacentsaid opening of said receiver means, said one end of said bolt beingcarried into said receiver opening to a second position by saidcompressed spring being released as said one end is moved off said fixedpart, said pin carried by said bolt as it is moved to said secondposition engaging the switch actuating means to complete the electriccircuit with the alarm means.
 2. A device as in claim 1 wherein saidlatch pin is formed of two pieces, one of which is inserted through theslot on the plate to connect with the other piece attached to the bolt.3. A device as in claim 1 wherein said switching means includes at leastone switch contact mounted on a leaf spring, said leaf spring comprisingsaid switch actuator means which is engaged by said latch pin. 4.Apparatus as in claim 1 wherein said fixed part adjacent said receivermeans engaged by said one end of said bolt comprises a step on saidreceiver means recessed from the exterior of said receiver means.
 5. Alock and alarm device comprising a housing including an upstanding walldefining an opening, a guide bolt casing formed on the interior of thehousing and having a central bore which terminates at one end in anopening at said housing wall and at the other end at a wall of saidcasing, said casing also formed with a through slot into said borehaving a first portion generally parallel to the longitudinal axis ofthe bore along part of the length thereof and a second portion which isat an angle to said first portion, a bolt in said casing bore and aspring between one end of said bolt and said casing wall at said otherend of said bore, a latch pin attached to said bolt and movable in saidslot, audible alarm means located in said housing, switch means in saidhousing connected in electrical circuit with said alarm means and havingan actuating means in the path of travel of said latch pin, said pinwhen resting in a first position on the wall of said second portion ofsaid slot holding said bolt in its retracted position and said spring ina compressed condition in said bore, said pin when fully released fromsaid first position carried by said bolt as it is moved by the releasedspring to a second position engaging the switch actuating means tocomplete the electric circuit with the alarm means, a cover plate forsaid housing, said cover plate having a slot therein which generallycorresponds to the shape of the slot in the bolt casing and is adjacentthereto, said latch pin formed of two pieces, one of which is attachedto said bolt and the other of which is inserted through said slot of theplate to connect with said one piece.
 6. A device as in claim 5 whereinsaid slot in said plate has an elongated generally straight firstportion corresponding to said first portion of the casing slot, and acurved second portion defining a projection in the plate, said pin beingmovable in said curved second portion around the plate projection toplace said latch pin in said first position.